Safe door construction



Aug. 11, 19 4 R. w. MAYNARD SAFE DOOR CONSTRUCTION Original Filed July 10. 1961 I NVENTOR.

A 7' 7' Jill/6'15 United States Patent 4 Claims. (Cl. 109-64) This invention relates to an improved door construction for money safes and the like. More specifically, the invention relates to a safe door construction which provides a tight, nonbinding interfit between the safe door and the body opening of such safes.

This application is a division of my co-pending application Serial No. 122,804, filed July 10, 1961.

Money safes are relatively small safes which are widely used in business establishments to protect cash and valuables against burglary and holdup. Typically, a money safe is provided with a generally round, inwardly tapering door having lugs at spaced positions around its inner face which are engageable behind body lugs mounted around the inner edge of the door opening to positively hold the door in closed position. The door is swingable about a vertical hinge at one side, and is also rotatable about a horizontal axis to engage or disengage its lugs behind the body lugs. Usually the door must be rotated about A; of a turn to completely engage or disengage its lugs from the body lugs. The lugs faces are not inclined relative to the body opening, as screw threads, but rather are perpendicular to the axis of the door, so that the closing action is smooth and does not bind.

It is conventional to provide an inward taper on the edges of both the door and the body opening to obtain a tight fit between the door and body opening, so that the edge of the door will facially abut the edge of the opening. Ideally the lugs are so positioned that when the door edge engages the opening, the door lugs will just slide behind the body lugs and there will be no play of the door in the opening and no crack is presented between the door and body through which the safe might be subject to attack.

In commercial practice, individual hand fitting has usually been required to fit the lugs relative to each other so that the door lugs will just clear behind the body lugs when the door is snugly fitted in the opening. The need for such fitting partly stems from the fact that it is difficulty to produce the tapered surfaces of the door and body opening so that they will exactly fit; the door opening surface might, for example, be a little high at one point, which will prevent the door from fitting into the body opening as far as it would if the surfaces fitted more perfectly, and therefore its lugs cannot be engaged behind the body lugs. It is also difficult to precisely position the body lugs as they are secured to the body; they are usually fastened to the body by welding. Errors of even .001 inch in the axial position of the bearing faces of either set of lugs may thus cause a poor or unacceptable interfit of the door in the opening. It has therefore been necessary in the past to fit each door to its body opening by hand trimming of the lugs.

One of the objects of the present invention has been to provide an improved construction for such safes whereby a proper interfit of the door in the body opening may readily be obtained in commercial practice. 7

Because of the exceptionally close fit between the safe door and body opening which is required, it occasionally happens that'particles of dirt or grit on either the door edge or the edge of the body opening tend to cut into the contacting surfaces as the door is rotated about its horizontal axis to engage or disengage its lugs with the body lugs. As the door is rotated, such small particles are Patented Aug. 11., 1964 rolled between the two meeting surfaces and, if the particle of grit is harden than the material of which either the door or body is made, may tend to weld the door to the body so that the safe cannot readily be opened. Since these edges are usually covered with a thin film of oil for protection against rust, particles or grit actually tend to accumulate on them, and such sticking is not infrequent.

Another object of the present invention has been to provide a tight-fitting safe door construction which prevents door sticking or welding caused by the action of grit particles.

In accordance with a preferred embodiment of the present invention, the safe body is provided with at least one lug which is partially split in a plane parallel to the general plane of the body opening. One face of the lug is welded to the inside of the body adjacent the door opening, and a portion of the lug projects into the door opening in position to interfit with a door lug. A tapered head screw is threaded into the lug longitudinally along the split. As the screw is threaded into the lug, its tapered head bears on the opposite sides of the split, forcing them relatively apart, so that the effective thickness of the lug is increased, thereby in effect positioning the inner face of the lug further inside the body opening. By threading the screw into or out of the lug, the inner face of the lug may be very exactly positioned relative to the forward or bearing surface of the corresponding door lug, so that when the door is snugly fitted in the body opening, this inside surface will smoothly engage the forward face of the door lug. Manufacturing tolerances are therefore not so critical, and looseness of the door in the body opening can easily be taken up by adjusting the screw in the lug.

The edge of the door is engraved or knurled with a plurality of fine lines in the region where the door edge engages the body opening. I have found that these lines, the pattern of which is not critical and may be arbitrary, serve as wipers to effectively prevent any grit particles which may be adherent to either surface from galling or welding the surfaces together. Particles of grit which cling to the surfaces are apparently rolled or wiped into these lines so that they cannot cause binding between the two surfaces.

The invention may best be further described in relation to the accompanying drawings, in which,

FIGURE 1 is a perspective view of an open money safe having a door construction which embodies the principles of the present invention;

FIGURE 2 is a vertical cross section through the top portion of a safe body and door, showing a split lug in accordance with the invention fitted to the body, and adjusted to provide a snug fit between the door and body opening, and also showing a series of engraved lines around the edge of the door;

FIGURE 3 is a front view of the lug shown in FIG- URE 2, showing the tapered head screw whereby the depth of the lug is adjusted; and

FIGURE 4 is a top view of the lug shown in FIG- URE 3.

A typical money safe is shown in FIGURE 1 and is designated generally by 10. The safe body 11 is provided with a circular opening 12 at its front 13. The body opening 12 has a conically tapered edge 14 against which the safe door 16 fits. Several lugs 17, 18, 19, and 20 are secured inside the body and project into the opening 12 in position to engage the door lugs to be described. One or more of the body lugs 17-20 may be split lugs in accordance with the invention, but in a small safe such as that shown it is sufiicient to use only a single split lug. The position of the split lug in the opening is not critical, but for purposes of description it is assumed that lug 20 at the top of the opening is the split lug. The other lugs 17, 18, and 19 are conventional in design.

The door 16 is round and is rotatable about a vertical hinge 22 at its side, so that it may be swung into and out of the door opening 12. The door is also rotatable about a horizontal axis, so that it can be engaged with the body lugs, as is hereinafter described. A handle 23 is secured to the door for effecting such rotation.

The edge 24 of the door is conical, and its taper generally corresponds to the taper of the edge 14 of the body opening. It is conventional to provide a slightly greater taper on the door edge 24 than on the body edge 14, so that the two edges are actually in contact only at and adjacent the front of the opening 12, as at 26 in FIGURE 2, and diverge very slightly inwardly of the area of contact, as is shown in greatly exaggerated fashion at 27.

Around the inner face of the door 16 several lugs 29, 30, 31, and 32 are formed or provided. A groove 33 slightly wider and deeper than the body lugs extends around the door forwardly of the door lug 29-31. The front wall of this groove is designated by 34, the respective forward faces 36 of the door lugs 29-32 incompletely defining the other side of the groove 33. The circumferential spaces between the respective door lugs 29-32 are Wider than the corresponding dimension of the body lugs 17-20, so that the body lugs will clear the door lugs as the door is swung closed in the angular position shown in FIGURE 1.- I

The split lug 20 is best shown in FIGURES 2, 3 and 4. It comprises a generally rectangular block which is partly divided in longitudinal direction by a split 37. This split may be formed in any suitable manner, for example by sawing. The split extends for about /3 or of the longitudinal dimension of the lug, to a transverse drill hole 38 which delimits its inner end. An adjusting screw 41 having a tapered head 42 is received in a tapped hole 43 which extends longitudinally in the solid end of the lug. The head 42 of the screw 41 bears on the sides of a bore 44 of larger diameter than hole 43, and cams the split halves of the lug apart as it is tightened into' the lug. The screw 41 may be an Allen screw.

One side of lug 21) is secured to the inside wall 39 of the safe body 11, for example by welding as indicated at 47. The inner surface 48 of lug 20 is free to move slightly inwardly or outwardly as the screw 41 is loosened or tightened in the lug. The forward side 49 of the lug which projects into opening 12 is preferably faced off to provide a clean appearance after the lug is welded to the body.

The thickness or depth of the split lug 20, i.e. its dimension in horizontal direction in FIGURE 2, is such that, when the adjusting screw 41 is not tightened into it, the inner face 48 of the lug is spaced slightly forward of the forward face 36 of the door lug 29, so that it does not engage face 36. The other body lugs 17-19 are similarly positioned. With the safe door 16 closed and its lugs engaged behind the respective body lugs, there will therefore be some looseness of the door in the body opening; the door will not be held in the opening as tightly as it properly should, since the inner faces of the door lugs, in particular lug 29, are not held sufficiently inwardly. This play or looseness is taken up by tightening the screw 41 into split lug 20, thereby positioning the inside face 48 of the split lug 20 further inwardly, until face 36 of door lug 29 is smoothly slidable over it as the door is turned intoclosing or opening position. The forward face 49 of the lug is spaced slightly rearwardly of face 34 of groove 33, as shown in FIGURE 2.

I have found that in such a construction it is possible to obtain an extremely close fit of the door in the door opening. Tedious individual fitting is obviated. The edge 14 of body opening 12 can be finished on a lathe, as can the edge 24 of door 16, since slight imperfections in the tapered surfaces can be relieved simply by adjusting the screw 41. Moreover, the lugs do not need to be so accurately positioned in the body. It will be understood that while only the split lug 20 facially engages a door lug, the other body lugs being spaced slightly forwardly of the other door lugs, the other body lugs would nonetheless positively abut the door lugs if it were somehow attempted to pry or blow the door open, since the clearance is small.

While I have shown the split lug as being secured to the body, it will be understood that it is alternatively possible to provide the door with a split lug of the type shown, such that the position of the front face of the door split lug is adjustable. Such mounting of the split lug would enable the same closeness of fit to be attained as in the preferred embodiment shown in the drawings.

The door 16 is provided with a series of fine engraved or knurled lines 51 around it over the general region 26 where the door edge facially contacts the edge 14 of the body opening. These lines are preferably about .003 to .005" deep, are spaced by about and are parallel to each other and perpendicular to the direction of rotation of the door. As previously explained, I have found that these lines function as wipers to prevent grit between the surfaces 14, 24 from binding or welding the surfaces together and thereby causing the door to stick. The pattern, spacing and depth of the lines is not particularly critical, although a regular uniform pattern such as that shown is preferred since it is easily applied. The lines may alternatively be formed on the edge 14 of the body opening, or on both edges 14 and 24. The lines should extend over the entire general area where the door and body opening edges contact each other.

While it is desirable to utilize the engraved lines 51 in conjunction with the split lug, each may be used without the other.

While I have described the preferred embodiment of my invention, it will be understood that the invention is not limited thereto, but is susceptible of various embodiments falling within the scope of the claims which follow.

What is claimed is:

1. A safe door construction comprising, a body, said body having a circular opening therethrough, said opening having a tapered edge, a door for closing said opening, said door having a tapered edge which facially engages the tapered edge of said opening when said door is in closing position in said opening, one of said edges being provided with a series of shallow grooves knurled therein, said grooves acting as wipers to prevent particles of grit from causing said door to stick in said opening.

2. In a safe of the type which includes a body presenting a circular opening thereinto, said opening having a tapered edge, and a circular door having a tapered edge, the respective edges of said door and said opening being adapted to contact each other over at least a portion of their areas when said door is in closing relationship with said opening, the improvement which comprises, a plurality of fine transverse lines knurled in at least one of said edges in the portion thereof which contacts the other tapered edge, said lines being about .003 to .005 inch deep, whereby sticking of said door in said opening caused by adherent grit is prevented.

3. The improvement of claim 2 wherein said lines are parallel to each other and approximately perpendicular to the plane ofsaid door.

4. The improvement of claim 2 wherein said lines are spaced from each other by about References Cited in the file of this patent UNITED STATES PATENTS 1,056,015 Fish Mar. 18, 1913 1,180,256 Cary Apr. 18, 1916 1,561,745 Redfield Nov. 17, 1925 1,966,402 Barringer July 10, 1934 

1. A SAFE DOOR CONSTRUCTION COMPRISING, A BODY, SAID BODY HAVING A CIRCULAR OPENING THERETHROUGH, SAID OPENING HAVING A TAPERED EDGE, A DOOR FOR CLOSING SAID OPENING, SAID DOOR HAVING A TAPERED EDGE WHICH FACIALLY ENGAGES THE TAPERED EDGE OF SAID OPENING WHEN SAID DOOR IS IN CLOSING POSITION IN SAID OPENING, ONE OF SAID EDGES BEING PROVIDED 